Vertebrate Natural History
Final Exam Study Guide (not cumulative: Lectures 20-27)
1. Label this phylogeny tree.
2. Define thermoregulation. a. Regulation of body temperature. i. Essential for most tetrapod's ii. Some climes too hot, some too cold 3. Define Ectotherms. a. Animals that gain heat from external sources in order to raise body temp b. Ancestral form; lower metabolic rate c. Ex: non-amniotes, turtles, lizards, snakes, & crocodilians 4. Define Endotherms. a. Animals that gain heat from metabolic processes in order to raise body temp b. Derived form; higher metabolic rate c. Ex. Birds, mammals 5. What are some examples of how ectotherms and endotherms are not mutually exclusive? a. Ex: pythons heating eggs b. Ex: roadrunners basking in sun 6. Label this diagram.
7. What are some ways heat can be gained as well as lost? a. Gain i. Directly ii. Reflected ii. Conduction iv. Convection b. Lost i. Conduction ii. Convection iii. Evaporation iv. Breathing 8. Define specific dynamic action. a. Increased heat production associated with digesting food 9. Label this diagram.
HEAT
a. 10. Define zone of tolerance. a. Range of temps. Over which body temp. can be kept stable. b. Above ZOT, cannot dissipate heat die! c. Below ZOT, heat loss > heat production & die! 11. Define Thermoneutral zone. a. Range of temps where metabolic rate is standard. b. Regulate by altering rate of heat loss (change in posture, etc.)
12. Define lower critical temp. a. Point where heat production must be increased. b. Metabolism and/or shivering 13. Label this diagram. Zone of tolerance
a. 14. Define lower lethal temp. a. Metabolic heat production maximized, but still not able to elevate body temp. b. As body temp. Drops, chemical reactions sensitive to temp metabolism slows, positive feedback into hypothermia. 15. Define Upper critical temp. a. Nonevaporative heat loss maximized b. Must use evaporative cooling for further heat loss i. Sweat, pant, etc... 16. Define Upper lethal temp a. Evaporative cooling maximized, but still not able to reduce body temp b. As body temp. rises, metabolism increases, positive feedback into hyperthermia 17. Define Torpor. a. Short-term (night or days) reduction of metabolic activity, body temp b. Spurred by air temp., food availability c. E.g., Black-capped chickadees d. Daytime body temp: 40-42'C e. Nightime body temp: 29-30C f. Relies on less fat reserves to maintain lower body temp, if not bird would starve 18. Define Hibernation. a. Long-term (week or months) form of torpor b. Spurred by photoperiod, hormonal changes 19. How can an animal maintain stable body temp in cold environments? a. Increase heat production i. Not practical -> need to increase food intake